There are typically three classes of storage system, low, mid and high (enterprise system). Components used in each of these classes of storage system can greatly vary in performance, cost, and functionality. This is attributed largely to differing requirements between each of the classes. Generally, low end systems use cheaper components than their high-end counterparts and do not offer component redundancy. Enterprise systems on the other hand use more expensive components and exhibit component redundancy, which provides higher reliability. Typically, low-end storage systems do no share common components with high-end systems. Low-end storage systems use different chassis, power supplies, fans, RAID controllers, application motherboards/HBAs blades, drive sleds, switches, etc.
Enterprise storage systems typically have a number of different building blocks, interconnect cables, field replaceable units (FRUs), system setup/configuration, and troubleshooting. Additionally, enterprise storage systems typically include integral switches for scalability and double the components for redundancy, and are generally not built with the same common components as low-end platforms.